Gas turbine driven supercharger



Jan. 6, 1942. E. B CLARKE 2,269,181

' GAS TURBINE DRIVEN SUPERCHARGER Filed Opt. 27, 1959 Inventor: Edward EaCiarKe,

His Attorney.

Patented Jan. 6, 1942 UNITED GAS TURBINE DRIVEN SUPERCHARGER Edward B. Clarke, Lynn, Mass., assignor to General Electric Company, a corporation of New York Application October 27, 1939, Serial No. 301,638

1 Claim.

The present invention relates to gas turbine driven superchargers comprising a compressor and a gas turbine having a bucket wheel secured to an overhung shaft of the supercharger and exhausting directly into the atmosphere. Gas turbine driven superchargers are often used for supercharging combustion engines, especially in aircraft power plants. In arrangements of this kind it may occur that solid objects such as washers, nuts, bolts and the like may 'become loose during operation and drop into pockets formed by the turbine bucket wheel and adjacent parts. Also, during assembly of such plants it may occur that solid I objects are inadvertently dropped into such pockets and left there. This endangers the operation of such power plants, particularly when such solid objects are forcefully thrown against the highly stressed bucket wheel during operation.

The object of my invention is to provide an improved gas turbine driven supercharger arrangement whereby the bucket wheel is effectively protected against contact with loose solid objects.

For a consideration of what I believe to be novel and my invention, attention is directed to the following description and the claim appended thereto in connection with the accompanying drawing.

The single figure of the drawing illustrates an arrangement embodying my invention, the compressor being shown in elevation and the turbine in section.

The arrangement comprises a centrifugal compressor III with an inlet II and a discharge conduit l2. The compressor is driven by a gas turbine including a bucket wheel I3 secured to The protecting wall I8 is supported on the supercharger by means including studs l9 and bolts 20.

The nozzle box I6 has a row of nozzles 2| for properly directing operating gases towards a row of buckets 22 of the bucket wheel l3. The row of nozzles 2| and the adjacent row of buckets 22 form a small clearance 23. It is important that any solid objects be prevented from contacting the bucket wheel during operation, especiallyin proximity to the clearance 23, because the bucket wheel is normally rotated at high speed and contact of loose, solid objectswith it might prove fatal to the arrangement. This is accomplished by the provision of an annular screen 24 between the compressor and the nozzle box. The screen 24 has edges secured to annular flanges 25 and 26 of the compressor and the nozzle box respectively by means including screws 21 and washers 28. During operation, cooling air may pass through the screen 24 in the direction of the arrows to cool the bearing I5 and the bucket wheell3. Access of solid matter is prevented by the screen 24 In the present instance cooling air from a suitable source, such as the slip stream of an airplane, is conducted to the outer surface of the bearing l5 by means of a flanged conduit 29 secured to the nozzle box and the casing of the compressor l0.

an overhung portion of the supercharger shaft l4. The shaft I4 is supported by a bearing l5 arranged between the bucket wheel l3 and the compressor Hi, the impeller of the compressor being carried by the shaft. Operating gases are conducted to the bucket wheel l3 by means including an annular nozzle box IS with an inlet l1 and concentrically spaced from the bearing IS. A partition I8 is provided between the nozzle box it and adjacent portions of the bearing l5 and the compressor 10 to reduce heat transfer from the nozzle box to the bearing and the compressor.

What I claim as new and desire to secure by Letters Patent of the United States is:

Gas turbine driven supercharger arrangement comprising a compressor having a shaft, a bearing supporting an intermediate portion of the shaft, a gas turbine having a bucket wheel secured to the shaft and an annular nozzle box for conducting gas to the wheel concentrically spaced from the bearing, cylindrical flanges being formed on adjacent portions of the compressor and the nozzle box, means comprising a conduit secured to the flanges for conducting cooling air to the bearing and the bucket wheel, and means including a cylindrical screen with edges secured to the flanges of the compressor and the nozzle box and having a portion extending across said conduit to prevent solid objects from entering the space between the nozzle box and the bearing.

' EDWARD B. CLARKE. 

